We propose to develop and test an innovative portable constant-tilt defibrillator with an LCD ECG monitor. The design approach is based upon years of defibrillation research which has resulted in defibrillator design equations for optimal use of energy. Constant-tilt control provides compensation for high thoracic impedance by automatically increasing the duration of the truncated exponential waveform. The efficacy of the prototype will be tested on pigs by the research team at Purdue. Also during Phase I, a marketing strategy will be developed with the Cook Group, Inc., who plan to market the device. Principal investigator, Dr. Neal E. Fearnot, the staff of the Medical Engineering and Development Institute, and the research team of the Biomedical Engineering Center of Purdue University, together, are able to complete the proposed task.